AbstractA revision of field data and new biostratigraphic analyses have highlighted that the lowest part of the Poggio Carnaio Sandstone Fm consists of greyish marls, formerly attributed to the Antognola Marl Fm, and that calcareous nannofossil assemblages from these marls as well as from the overlying turbiditic sandstones are characterized by some taxa first occurring in Tortonian. Moreover, the occurrence of Discoaster cf. berggrenii could suggest an age not older than late Tortonian for the studied succession.
The Poggio Carnaio Sandstone Fm, therefore, from its base is not older than Tortonian and constitutes a thrust-top basin unconformable succession, deposited on sub-ligurian units.

AbstractMudrocks and sandstones of Numidian Formation in Sicily have been analysed for mineralogical, petrographic, major element and selected trace element compositions to constrain the intraformational variability and the sediment provenance. The mudrocks are characterized by a kaolinite-rich signature while the sandstones have a quartz-arenitic composition. The high Chemical Index of Alteration and Plagioclase Index of Alteration strongly suggest that recycling processes have been responsible for the present compositions.
The mudrocks geochemical data suggested a compositional variability function of the paleogeographic depositional environments.
In particular, the Numidian Formation of the more external Serra Del Bosco Unit is affected by the terrigenous contribution of epicontinental-type sediments. With regard to provenance, the geochemical data indicate a derivation from post-Archean sedimentary siliciclastic rocks. The contribution of African cratonic sediments was confirmed by the trace elements ratios and by the end-member modeling processed on mudrocks compositional data. In particular the suitability of the Nubian sediments as one of the sources of sediment supply is also attested.

Pliocene to Quaternary evolution of the Ofanto Basin in southern Italy: an approach based on the unconformity-bounded stratigraphic units

Volume:133 (2014) f.1 Pages:27-44 https://doi.org/10.3301/IJG.2013.11

Abstract

AbstractThe Ofanto Basin is an actively evolving intra-chain basin of the Southern Apennines, Italy. It has an elongated shape, about 7 km large and 45 km long, and is E-W striking, representing a marked bend in the NW-SE regular orientation of the south-Apennines morphostructures.
The basin is filled up by Pliocene to Quaternary clay, sandstone, and conglomerate, deposited in both marine and continental environments. The main sedimentary deposits are grouped into six units bounded by stratigraphic discontinuities marked by unconformities and abrupt lithological variations. Three of those discontinuities are recognisable on a regional scale and represent the physical boundaries of three supersynthems, in turn subdivided into synthems and subsynthems by basin-scale unconformities. The sedimentary evolution of the basin is herewith reported. Facies analyses and architecture of the sedimentary bodies revealed that each unit formed different alluvial and deltaic depositional systems located on the southern and northern margins of the basin. The morphology of the northern slope was probably steeper than the southern one. The oldest units were deposited in the Western sector of the Ofanto basin. Starting from the late Zanclean to the early Gelasian, the sedimentary bodies underwent an Eastward shift in their deposition, suggesting a basinward relocation of the depositional systems. Such variations in time and space seem to reflect relevant changes in accommodation space and sedimentary supply during the tectonic evolution of the basin. Eventually, correlations among adjacent basins and the meaning of the discontinuities as former erosional surfaces have been pointed out.

AbstractThe biostratigraphy, fusulinid and microfacies from the Permian succession of the Shaksgam Valley (Aghil and Karakorum ranges) are described. The succession starts with a terrigenous prism, consisting of shale and siltstone covered by litharenite, several hundreds m-thick.
They represent an alluvial to shore-face terrigenous prism, on which gradually progrades a marine shallow water complex with bioclastic calcarenite and wackestone/mudstone. A reappraisal of the litharenite also with hummocky cross-lamination is overlain by progressively deeper mudstone/wackestone, and cherty limestone. Very thick calciruditic and pebbly limestone bodies are interbedded in the cherty limestone, in turn newly overlain by marls and shales, followed by thin bedded mudstone.
Four fusulinid assemblages are identified, bottom to top: Mono - diexodina (Yakhtashian-Bolorian), Leeina-Chalaroschwagerina (Bolorian),
Cancellina-Pseudodoliolina-Parafusulina (Late Kubergandian), and Dunbarula-Codonofusiella (Late Murgabian-Midian) respectively. Two new Leeina species are described, Leeina karakorumensis Leven, and Leeina ellipsoidalis Leven.

AbstractIn the Southern Alps (NE Italy), within the Giudicarie fault zone, Middle to Upper Eocene deep-water foredeep succession includes volcanic layers, pebbles from porphyric dykes and volcaniclastic sandstones, testifying the occurrence of Eocene volcanic activity from unknown volcanic centres. In this paper, we report petrographic, geochemical and chronostratigraphic characteristics.
Both the volcanic layers and the pebbles share their petrographic and geochemical characteristics with calc-alkaline igneous activity of the nearby Eocene Adamello batholith, as well as with dykes from the Eastern Lombardian Alps and the Southern Alps basement, in the proximity of the Giudicarie fault zone. All of these rocks have incompatible element ratios typical of orogenic magmas (e.g., high Th/Yb and La/Nb, and low Ta/Yb, Nb/U) in contrast to that observed for the coeval anorogenic Veneto volcanic rocks. In addition, the studied Eocene calc-alkaline rocks also differ in part from the Oligocene calc-alkaline ones distributed along the E-W oriented Periadriatic fault system in terms of trace element distribution and incompatible element ratios. The Oligocene rocks are generally more enriched in incompatible elements than the Eocene ones and show higher Zr/Y but lower Nb/Y ratios. The set of data presented in this paper allows us to advance new insights on the evolution of Tertiary magmatism in the Alps, which was probably developed through a NE-SW-oriented magmatic arc during Eocene and an E-W-oriented magmatic arc during Oligocene. The two events are marked by different geochemical features of the magmatic products.

AbstractResedimented calcarenites and hybrid arenites are commonly found interbedded with various Upper Miocene terrigenous units (hemipelagic marls, "brecce della Renga fm.", and siliciclastic turbidites) across the Simbruini Mts. and neighbouring areas of Central Apennines. Their distribution provides evidence for a complex, and rapidly evolving, paleogeography across a region that was experiencing the transition from foreland to accretionary wedge conditions during the Tortonian and Messinian. The bio-sedimentological features of the calcarenites indicate deposition through gravity flows (turbidity currents) sourced by areas of active benthic, heterozoan-type carbonate
production, locally lying at photic depth. Thin-section analysis of >130 samples revealed that the resedimented levels are mainly composed by bioclastic calcarenites, with fragments of bivalves, echinoids, bryozoans, balanids, benthic foraminifera, anellids and red algae, along with subordinate planktonic foraminifera. The calcareous turbidites in the hemipelagic marls (Unità argillosomarnosa) are characterized by the presence of Heterostegina sp., and their main source area was probably lying east, on the undeformed foreland. In contrast, evidence from field mapping, their common association with Cretaceous and Miocene carbonate lithoclasts, and the age of the encasing units, all suggest that the calcarenites in the "brecce della Renga fm." and in the siliciclastic turbidites ("complesso torbiditico altomiocenico laziale-abruzzese") could most likely have a different source.
The presence of a carbonate ridge, corresponding today to the NW sector of the Simbruini range, bordered by normal faults exposing the Cretaceous substrate, is proven proven by mappable paleo - escarpment tracts onlapped by clastic and hemipelagic deposits.
This ridge could have fed surrounding deeper areas with a mixture of lithoclasts and loose bioclastic material, produced through erosion of exposed bedrock coupled with export of sediment that was being produced topping and fringing the footwall blocks and their marginal downsteps. Carbonate production was apparently able to survive for a limited time in small productive areas until the early Messinian, shedding sediment into the siliciclastic foredeep

AbstractThe composition of Plio-Pleistocene fine-grained sediments from different areas of Calabria (southern Italy), have been studied to unravel the interplay of provenance. The use of multivariate statistical methods (e.g., PCA) based on biplot, allows for the discrimination of different groups of sediments. The general chemical composition of the fine-grained samples reflects the mineralogical variation observed in the sediments, which are composed of phyllosilicates, quartz, calcite, dolomite and feldspars. The I-S mixed layers, 10 Å-minerals (illite and micas) are the most abundant phyllosilicates, chlorite and kaolinite are present in variable amounts, and smectite and chlorite/smectite mixed layers are presents in trace amounts. These chemical and mineralogical variations are also confirmed by SEM analysis, which also demonstrates that phyllosilicates are characterized by open and folded structures with generation of neoformed clay minerals. Provenance proxies and element ratios testify greater input of felsic source rocks, with lack of a marked mafic-ultramafic detritus input for all studied sediments, and the minero-petrographical features of the studied fine-grained sediments. These chemical and mineralogical variations are also confirmed by SEM analysis showing abundant phyllosilicate minerals for Groups 1 (Crotone Basin) and 2 (Crati Graben) and high content of quartz and feldspars grains for Group 4 (Catanzaro Graben) samples, probably due to abundant siliciclastic input coming from plutonic-metamorphic source and associated Mesozoic to Miocene sedimentary sources (Sila and Serre Massifs), and abundant calcium-carbonate phases mainly related to the presence of planktonic calcareous microfossils (Globigerina and coccoliths) for Groups 3 (southern Ionian coast) and 5 (southern Tyrrhenian coast).
Furthermore, paleogeographic reconstructions characterized by re-establishment of open-marine conditions in the Mediterranean following the Messinian salinity crisis at the beginning of the Pliocene, play an important role. A progressive increase in the connectivity of Mediterranean sub-basins with the Atlantic (e.g., subbasins at the south of the Catanzaro Strait, characterized by normal water supply) and Paratethys (e.g., sub-basins at the north of the Catanzaro Strait, characterized by freshwater supply) can be envisaged during the Neogene period; this paleogeographic reconstruction may also explain the different composition among the studied samples.

AbstractFacies analysis and ichnology in a foredeep system of the Lower Miocene Macigno Formation, N of Lake Trasimeno (Umbrian Apennines, Italy), show that ichnoassemblages, developed into several ichnocoenoses - typical ichnotaxa and their stratinomic position in different facies - can be diagnostic indicators for siliciclastic and carbonatic gravity flow deposits. Ichnologic analysis allows defining palaeoecological adaptations in deep-sea burrower organisms, as already applied successfully in other deep-sea environments of Cenozoic turbiditic successions of Italy and Spain.
Fourteen sections of the three members of Macigno Formation, some of these revisited in this work, contain ichnocoenoses, differing among distal lobes, inter-lobes deposits (hemipelagic mud), lobe fringes and mud turbidites. The use of ichnocoenoses (e.g. the Halopoa-Spirophycus-Spirorhaphe ichnocoenosis with the fucusopsis preservation of the ichnogenus Halopoa), described here for the first time, underline, rather than classical ichnofacies (Nereites) or ichnosubfacies, the usefulness of ichnology in foredeep basin analysis.

AbstractThis study focuses on facies analysis and depositional architecture of the Arente shelf-type delta, located at the southernmost margin of the Pleistocene Crati Basin (northern Calabria, southern Italy). Tectonically-controlled Gilbert deltas are extensively discussed in the literature, whereas few works document shelf-type deltas and factors controlling sedimentation. This paper contributes to these issues, with a special focus on evaluating eustatic and tectonic control on depositional architecture also by considering the occurrence of coeval Gilbert-delta systems.
The Arente delta complex represents part of the coarse-grained sediments presently exposed along the eastern margin of the Crati Basin. It was sourced from the rising Sila Massif to the E and shows an overall westerly progradation.
Conventional sedimentological analysis allowed to distinguish seven different facies associations. Well-exposed sections, at the basin margin, generally show an overall upward transition, locally basinward, from mouth-bar conglomerates and sandstones, to deltafront sandstone, to offshore mudstones. Facies distribution and arrangement are interpreted as the record of a shoal-water fan delta.
Depositional processes were clearly influenced by the high sediment input, with a dominance of hyperpycnal deposits.
Based on the occurrence of a series of bounding surfaces indicating abrupt drowning stages, the Arente deltaic succession can be divided into 5 distinct transgressive-regressive sequences.
The fining and the thinning upward trend of the whole succession and the stacked landward-stepping architecture of the transgressiveregressive sequences, i.e. the E-directed retrogradational behavior of the Arente delta complex indicate that.
Tectonic subsidence provided the accommodation space for the deposition of the delta complex, for the marked local backstepping of the system, and for the progressive drowning of bedrock. Highfrequency sea level fluctuations led to the repeated arrangement of the facies associations; in particular, the stacking of the individual deltaic sequences separated by transgressive surfaces suggests amplitudes of eustatic sea-level changes of a few tens of metres, thus representative of a higher-order cyclicity. The differing internal architecture, if compared to the steeply-dipping foreset beds of the Gilbert-type delta cropping out to the N of the study area, is interpreted as due to a decrease in displacement toward the southern tip of the Crati system fault.

AbstractIn the historical buildings of eastern Logudoro (northern Sardinia), as well as in large areas of western Sardinia, ignimbritic rocks are widely used for ashlars and architectural elements as architraves, pedestals, shafts and capitals of columns. The decay processes affecting these rocks cause a progressive disintegration of the stone ashlars, with loss of material by exfoliation and flaking that determine a progressive retraction of the external profile of the façade with obliteration of the decorative elements. New data on the linear dilatation due to water absorption of these volcanic rocks are presented in this study in order to contribute to the evaluation of the impact of hydric dilatation in the stone degradation. The relationships among linear hydric dilatation of ignimbritic samples and petrographic and mineralogical characteristics as well as physical properties (texture, welding degree, porosity) indicate that three lithotypes with different behaviour in the water absorption can be distinguished in the ignimbrite rocks used as building stones in the church of Santa Maria di Otti (Oschiri, northern Sardinia, Italy). Although the linear hydric dilatation of the ignimbrites is moderate to low, we suggest that hydric dilatation may be an additional factor in enhancing the decay of the stones of the Santa Maria di Otti church.